Winchester Small Pistol Magnum Primers #1-1/2M Box of 1000

Clear Product Overview

Winchester 1 1 2M Primers (Small Pistol Magnum / WSPM) are engineered to deliver precise, high-intensity flame output required for positive ignition in small magnum handgun cartridges and hard-to-ignite spherical ball powders. Manufactured to strict quality standards, these non-corrosive, non-mercuric primers feature all-weather sensitivity and robust cup construction. Designed to prevent ignition delays and pressure spikes in compact, high-pressure cases, Winchester #1-1/2M primers allow handgun hunters and target shooters to achieve low standard deviations and ultra-consistent velocities.

Relevant Specifications

• Brand: Winchester Ammunition

• Product Line: USA Reloading Components

• Primer Type: Small Pistol Magnum (No. 1-1/2M / WSPM)

• Quantity: Box of 1,000 (10 individual sleeve trays of 100)

• Chemical Composition: Non-Corrosive, Non-Mercuric High-Output Priming Compound

• Cup Design: Heavy-Duty Precision Brass Cup

• Intended Applications: .357 Magnum, .327 Federal Magnum, .357 SIG (high-pressure loads), .22 Remington Jet, 9mm Luger (select slow/ball powder charges)

• Country of Origin: Made in the USA

Real-World Use Information

When loading high-velocity handgun cartridges using dense ball powders (such as Winchester 296 or Hodgdon H110), Winchester 1 1 2M Primers provide the sustained flame length needed for thorough powder combustion. Their precision cup geometry seats smoothly into small pistol primer pockets using hand-held priming tools, bench tools, or progressive press primer feeds. Furthermore, the clean-burning chemical formulation keeps cylinder gaps and action components free from excessive carbon residue.

Compatibility & Requirements

• Cartridge Compatibility: Fits all standard small pistol primer pocket brass (.357 Mag, .327 Fed Mag, .357 SIG, 9mm Luger).

• Equipment Compatibility: Seats cleanly using standard hand priming tools, bench tools, and progressive press priming assemblies (Dillon, Hornady, Lee, RCBS).

• Safety Requirement: Always wear protective eyewear during assembly, store primers in a cool, dry place away from heat sources, and never force a primer into an obstructed pocket.

Pros & Limitations

Pros:

• Intense Thermal Output: Generates a hot, sustained flame path designed specifically for slow-burning, high-volume pistol propellants.

• All-Weather Sensitivity: Formulated to perform consistently across extreme temperature fluctuations.

• Smooth Progressive Feeding: Dimensional consistency prevents jamming in auto-feed primer tubes.

• Non-Corrosive Chemistry: Protects precision bores and cylinder chambers from corrosive pitting.

Limitations:

• Not for Standard Low-Pressure Loads: Using magnum primers in standard non-magnum charges without dropping starting load data can cause unexpected pressure spikes.

• Specific Pocket Fit: Requires clean small pistol primer pockets seated flush to 0.002–0.006 inches below the case head for proper firing pin strike response.

Frequently Asked Questions (FAQs)

Q: What is the difference between Winchester WSP and Winchester WSPM (#1-1/2M) primers?

A: Winchester WSP is a standard small pistol primer, whereas WSPM (#1-1/2M) is a small pistol magnum primer. The WSPM produces a hotter, longer flame flash designed to ignite slow-burning powders commonly used in magnum handgun cartridges.

Q: Can I use Winchester 1-1/2M primers for loading .357 Magnum?

A: Yes, Winchester #1-1/2M primers are specifically designed for reloading .357 Magnum and other small pistol magnum cartridges.

Q: Do Winchester #1-1/2M primers work in progressive presses?

A: Yes, their uniform cup construction feeds cleanly and smoothly through progressive press primer tubes and shuttles.

Shipping & Delivery Information

• HazMat Classification: Ships as Hazardous Material (UN0044, Primers, Cap Type) under DOT rules.

• Shipping Restrictions: Ships by ground inside the Continental United States only. Therefore, we cannot ship to P.O. Boxes, APO/FPO locations, or overseas.

• Adult Signature Required: An adult must sign for the package upon delivery.

• Final Sale: Due to federal safety rules for hazardous materials, all primer sales are final and non-returnable.